Process for producing acids-enriched juice and acids-reduced juice

ABSTRACT

A method is described for processing fruit or vegetables, e.g., cranberries, into two different juices. One of the two juices has a relatively high level of acids. The other of the two juices has a relatively low level of acids. The method of the invention entails providing three juice streams. The first juice stream is passed through a nanofiltration apparatus or some other apparatus that is capable of preferentially removing acidic compounds from the raw fruit or vegetable juice feedstock. This process creates two juice fractions: a juice fraction that is relatively enriched in acids and a juice fraction that is relatively reduced in acids. The second juice stream is combined with the juice fraction that is relatively enriched in acids to create a juice that has a relatively high level of acids. The third juice stream is combined with the juice fraction that is relatively reduced in acids to create a juice that has a relatively low level of acids.

BACKGROUND

Fruits and vegetables contain a wide variety of compounds includingsugars, acids, and phytochemical compounds. Depending on the productdesired, it can be beneficial to have a relatively high level or arelatively low level of each of these compounds.

SUMMARY

A method is described for processing fruits or vegetables, e.g.,cranberries, into two different juices. One of the two juices has arelatively high level of acids (e.g., acids such as malic acid, quinicacid, and citric acid). The other of the two juices has a relatively lowlevel of acids. The method of the invention entails providing threejuice streams. The first juice stream is passed through a nanofiltrationapparatus or some other apparatus that is capable of preferentiallyremoving acidic compounds from the raw juice feedstock. This processcreates two juice fractions: a juice fraction that is enriched in acids(“an acids-enriched juice fraction”) and a juice fraction that isreduced in acids (“an acids-reduced juice fraction”). The second juicestream is combined with the juice fraction that is enriched in acids tocreate a juice that has a relatively high level of acids. The thirdjuice stream is combined with the juice fraction that is reduced inacids to create a juice that has a relatively low level of acids.

Fruit or vegetable juice that has a relatively high level of acids canbe used for a variety of purposes. Generally, it can be used in productapplications where increased acidity is deemed to be a desirablefinished product attribute. For example, it can be used in its pure formor combined with other juices to provide a juice or blended juiceproduct that is less sweet and more tart.

Fruit or vegetable juice that has a relatively low level of acids can beused for a variety of purposes. Generally, it can be used in productapplications where decreased acidity is deemed to be a desirablefinished product attribute. For example, it can be used in its pure formor combined with other juices to provide a juice or blended juiceproduct that is more sweet and less tart.

The invention features a method comprising: providing a fruit juice thatis substantially free of insoluble fruit solids; treating a firstportion of the fruit juice to preferentially remove acidic compoundsfrom the raw fruit juice feedstock, whereby an acids-enriched juicefraction and an acids-reduced juice fraction are produced; and combiningthe acids-reduced juice fraction with a second portion of the fruitjuice to create an acids-reduced fruit juice.

In various embodiments the method further comprises: combining theacids-enriched juice fraction with a third portion of the fruit juice tocreate a acids-enriched fruit juice; concentrating the acids-reducedfruit juice by removing a portion of the water therein; andconcentrating the acids-enriched fruit juice by removing a portion ofthe water therein. In one embodiment the fruit juice is cranberry juice.In one embodiment the step of treating a first portion of the fruitjuice comprises nanofiltration.

In another aspect, the invention features a method comprising: providinga fruit juice that is substantially free of insoluble fruit solids;treating a first portion of the fruit juice to preferentially removeacidic compound from the raw fruit juice feed stock, whereby anacids-enriched juice fraction and an acids-reduced juice fraction areproduced; and combining the acids-enriched juice fraction with a secondportion of the fruit juice to create an acids-enriched fruit juice.

In various embodiments the method further comprises: combining theacids-reduced juice fraction with a third portion of the fruit juice tocreate an acid-reduced fruit juice; concentrating the acids-reducedfruit juice by removing a portion of the water therein; andconcentrating the acids-enriched fruit juice by removing a portion ofthe water therein. In one embodiment the fruit juice is cranberry juice.In one embodiment the step of treating a first portion of the fruitjuice comprises nanofiltration.

Other aspects of the invention include: an acids-enriched fruit juiceprepared by a method of the invention; an acids-reduced fruit juiceprepared by a method of the invention; a blended juice productcomprising an acids-enriched fruit juice prepared by a method of theinvention; a blended juice product comprising an acids-reduced fruitjuice prepared by a method of the invention; an acids-enriched fruitjuice powder prepared by drying an acids-enriched fruit juice preparedby a method of the invention; and an acids-reduced fruit juice powderprepared by drying an acids-reduced fruit juice prepared by a method ofthe invention.

The invention also features a method comprising: providing a vegetablejuice that is substantially free of insoluble vegetable solids; treatinga first portion of the vegetable juice to preferentially remove acidiccompound from the raw vegetable juice feedstock, whereby anacids-enriched juice fraction and an acids-reduced juice fraction areproduced; and combining the acids-reduced juice fraction with a secondportion of the vegetable juice to create an acids-reduced vegetablejuice.

In various embodiments the method further comprises: combining theacids-enriched juice fraction with a third portion of the vegetablejuice to create an acids-enriched vegetable juice; concentrating theacids-reduced vegetable juice by removing a portion of the watertherein; and concentrating the acids-enriched vegetable juice byremoving a portion of the water therein. In one embodiment the vegetablejuice is tomato juice. In another embodiment the vegetable juice ispepper juice. In one embodiment the step of treating a first portion ofthe vegetable juice comprises nanofiltration.

In yet another aspect, the invention features a method comprising:providing a vegetable juice that is substantially free of insolublevegetable solids; treating a first portion of the vegetable juice topreferentially remove acidic compound from the raw vegetable juicefeedstock, whereby an acids-enriched juice fraction and an acids-reducedjuice fraction are produced; and combining the acids-enriched vegetablejuice fraction with a second portion of the vegetable juice to create anacids-enriched vegetable juice.

In various embodiments the method further comprises: combining theacids-reduced juice fraction with a third portion of the vegetable juiceto create an acids-reduced vegetable juice; concentrating theacids-reduced vegetable juice by removing a portion of the watertherein; and concentrating the acids-enriched vegetable juice byremoving a portion of the water therein. In one embodiment the vegetablejuice is tomato juice. In another embodiment the vegetable juice ispepper juice. In one embodiment the step of treating a first portion ofthe vegetable juice comprises nanofiltration.

Other aspects of the invention include: an acids-enriched vegetablejuice prepared by a method of the invention; an acids-reduced vegetablejuice prepared by a method of the invention; a blended juice productcomprising an acids-enriched vegetable juice prepared by a method of theinvention; a blended juice product comprising an acids-reduced vegetablejuice prepared by a method of the invention; an acids-enriched vegetablejuice powder prepared by drying an acids-enriched vegetable juiceprepared by a method of the invention; and an acids-reduced vegetablejuice powder prepared by drying an acids-reduced vegetable juiceprepared by a method of the invention.

The details of one or more embodiments of the invention are set forth inthe accompanying drawings and the description below. Other features,objects, and advantages of the invention will be apparent from thedescription and drawing, and from the claims.

DESCRIPTION OF DRAWING

The FIGURE is a flow chart depicting one embodiment of the invention.

DETAILED DESCRIPTION

Referring to the FIGURE, a flow diagram is shown of a process forpreparing two different fruit or vegetable juices: one that has arelatively high level of acids and one that has a relatively low levelof acids. The process can begin with any fruit or vegetable feedstock,e.g., fruit of the genus Vaccinium. In the embodiment of the Figure,fruit feedstock 15 from a fruit feedstock supply 10 is conveyed tooptional pulverization stage 20 where it is pulverized (e.g., using aUrshel, Inc. Comitrol Processor Model 1700), sliced, diced, chopped,ground, or treated in some other manner to reduce the fruit to a sizesuitable for efficient depectinization. The pulverized material 25 isconveyed to a depectinization stage 30 where it is treated withpectinase enzyme 35 provided by a pectinase enzyme supply 40 undersufficient conditions of time and temperature (e.g., about 2 hours at110° F.-120° F.) to enable effective depectinization of the fruit mashand thereby to afford the potential for good physical separation of theresulting solid and liquid phases. The depectinized material 45 is nextconveyed to an optional finishing stage 50 where it is passed through acontinuous screening device (e.g., a Langsenkemp, Inc. continuousscreening device with 0.033 inch openings) or otherwise treated toremove seeds, skins, twigs and the like 55 which are passed to a seeds,skins, and twigs collector 60. This finishing stage is optional, but isuseful for generating clean pomace. The finished material 65 passingthrough the continuous screening device is next conveyed to acentrifugation stage 70 where a centrifuge (e.g., Westphalia, Inc. ModelCA505) or other device, e.g., a press, is used to remove insolublesolids as a fiber-enriched pomace 75 which is conveyed to a pomacecollector 80. If finishing stage 50 is omitted, the seed, skins, twigsand other material that would be collected at 60 are instead passed tothe pomace collector 80.

After centrifugation stage 70, a fruit juice 85 is passed to amicrofiltration stage 90 where it is microfiltered (e.g., using a KochMembrane Systems, Inc. skid with a Koch Membrane Systems, Inc. modelMFK617 membrane) or effectively processed using some other separationtechnology to remove residual suspended insoluble solids 95 which arepassed to an insoluble solids collector 100. The permeate fraction is apolished fruit juice 105. The polished fruit juice ideally contains noresidual suspended solids.

The polished fruit juice 105 is passed to a ratio divert mechanism 110that divides the juice into three streams, 120, 130, and 140. The weightfraction of each stream can be selected according to user preference.For example, 20% of juice 105 can pass to juice stream 120; 40% of juice105 can pass to juice stream 130; and 40% of juice 105 can pass to juicestream 140.

Juice stream 130 passes to an nanofiltration stage 150 where it isnanofiltered (e.g., using a nanofiltration membrane that has a molecularweight cut off of about 400 Daltons, 350 Daltons, 300 Daltons, 250Daltons, or 200 Daltons). Alternatively, juice stream 130 is processedby some other means that preferentially removes acidic compounds fromthe polished unfractionated fruit juice feedstock. Thus, nanofiltrationstage 150 produces an acids-enriched permeate fraction 160 and anacids-reduced retentate fraction 170. In the case of cranberry juice,the permeate fraction thus preferably contains such organic acids asmalic acid, citric acid, and quinic acid. The nanofiltration step orother separation step need not effect completely efficient removal ofthe acidic compounds. For example, the acid-enriched fraction cancontain at least 10%, at least 20%, at least 30%, at least 40%, at least50%, at least 60%, at least 70%, at least 80%, at least 90%, at least95%, or at least 98% of one or more of the acidic compounds present inthe polished unfractionated fruit juice feedstock (e.g., acids such asmalic acid, citric acid, or quinic acid). As long as the acids-reducedretentate fraction and the acids-enriched permeate fraction aresignificantly different in the relative proportion of their acidscontent, the employed separation technique is deemed suitable.

The acids-enriched permeate fraction 160 passes to blender 180 where itis combined with juice stream 120 to a create a acids-enriched fruitjuice 190. The acids-enriched fruit juice 190 can optionally pass toconcentrator 200 to create an acids-enriched fruit juice concentrate210.

The acids-reduced retentate fraction 170 from nanofiltration stage 150passes to blender 220 where it is combined with juice stream 140 tocreate a acids-reduced fruit juice 230. This acids-reduced fruit juice230 can optionally pass to concentrator 240 to create a acids-reducedfruit juice concentrate 250.

The foregoing is a description of one embodiment of the method of theinvention. Those skilled in the art will be able to modify the process.For example, controlled atmosphere (e.g., N₂ or CO₂) techniques can beused during the depectinization and heat treatment stages to minimizethe deleterious effects of oxidative reactions.

In another modification enzymes in addition to or instead of pectinase(e.g., enzymes which digest cellulose) can be used in thedepectinization stage.

Extracted fruit produced by water extraction, e.g., countercurrentextraction, as described in U.S. Pat. No. 5,320,861, hereby incorporatedby reference, or the presscake/pomace discharge of conventional fruitprocessing techniques used in the production of fruit juice can be usedas the fruit feedstock. Moreover, instead of using whole fruit as afeedstock, leaves and other components of the fruit plant can be used.Alternatively, the fruit plant components can be used as a feedstock incombination with whole fruit.

A controlled heat treatment step can be included to increase the yieldof water soluble compounds. For example, the pectinase-treated mash canbe passed to a controlled high temperature heat treatment stage where itis heated to about 180° F. to further release water soluble compounds(e.g., phenolics, proanthocyanidins, and anthocyanins) bound to thesolid phase (pulp, skin, and seeds). In general, the heat treatment isgreater than 140° F. (e.g., at least 150° F., 160° F., 170° F., 180° F.,190° F., 200° F., 210° F., or 212° F.) and is carried out for a longerduration than the high temperature-short time (HTST) techniques that arecharacteristically used to deactivate enzymes naturally present in thefruit. Thus, the heat treatment preferably lasts for at least 1 minute,at least 2 minutes, at least 3 minutes, at least 5 minutes or even atleast 10-15 minutes or even longer (e.g., at least 20 minutes, 30minutes, or even 1 hour). The heat treatment can occur before or afterdepectinization, and depectinization is itself optional. For example,certain fruits, e.g., strawberries, may not need to be depectinized toafford the potential for good physical separation of the solid andliquid phases of the fruit mash resulting from heat treatment. Suitableheat treatment procedures are described in detail in U.S. Ser. No.09/611,852 (filed Jul. 7, 2000) hereby incorporated by reference.

Fruit juice produced by countercurrent extraction of cranberries can beused in the methods of the invention as follows. Countercurrentlyextracted fruit juice can be prepared as described in U.S. Pat. Nos.5,320,861 and 5,419,251, hereby incorporated by reference. Briefly,frozen whole raw cranberries are provided to a cleaning stage to removedebris such as twigs, leaves, etc. and then conveyed to a sorting stagewhich sorts fruit to a selected size. The size-selected fruit is thenconveyed to a slicing stage that slices the berries to expose the innerflesh of the fruit, unprotected by the skin. The whole cranberries arepreferably cut to provide slices between 6 to 8 millimeters in width.The cleaned, sized and sliced frozen cranberries are then defrostedusing hot water (e.g., at about 130° F.) to a temperature of less than75° F. (e.g., 65° F.) and conveyed to the solid input of an extractorstage which employs a countercurrent extractor described in detail inU.S. Pat. No. 5,320,861. The liquid input to the extractor is typicallyderived from a fruit-derived water supply. The liquid output of theextractor stage is a high-quality extract mixture of fruit-derived waterand fruit juice, which is collected for further treatment and use in themethods of the invention. In addition, the extracted fruit can be usedas a fruit feedstock to produce additional juice that can be used in themethods of the invention.

A number of embodiments of the invention have been described.Nevertheless, it will be understood that various modifications may bemade without departing from the spirit and scope of the invention. Forexample, fruit juices and vegetable juices can be processed together inany desired combination. Moreover, a fruit juice fraction can becombined with a vegetable juice and a vegetable juice fraction can becombined with a fruit juice. Accordingly, other embodiments are withinthe scope of the following claims.

What is claimed is:
 1. A method comprising: (a) providing a flow offruit juice that is substantially free of insoluble fruit solids; (b)dividing the flow of fruit juice into at least a first juice stream, asecond juice stream and a third juice stream by passing the flow offruit juice through a ratio divert mechanism; (c) treating the firstjuice stream to preferentially remove acidic compounds thereby creatingan acids-enriched juice stream and an acids-reduced juice stream; (d)combining the acids-reduced juice stream with the second juice stream tocreate an acids-reduced fruit juice; and (e) combining theacids-enriched juice stream with the third juice stream create anacids-enriched fruit juice.
 2. The method of claim 1, further comprisingconcentrating the acids-enriched fruit juice by removing a portion ofthe water therein.
 3. The method of claim 1, further comprisingconcentrating the acids-reduced fruit juice by removing a portion of thewater therein.
 4. The method of claim 1, wherein the fruit juice iscranberry juice.
 5. The method of claim 1 wherein the step of treatingthe first juice stream comprises nanofiltration.
 6. The method of claim1 further comprising combining the acids-enriched fruit juice with adifferent fruit juice to generate a blended juice product.
 7. The methodof claim 1 further comprising combining the acids-reduced fruit juicewith a different fruit juice to generate a blended juice product.
 8. Themethod of claim 1 further comprising drying the acids-enriched fruitjuice to generate an acids-enriched fruit juice powder.
 9. The method ofclaim 1 further comprising drying the acids-reduced fruit juice togenerate an acids-reduced fruit juice powder.
 10. The method of claim 1wherein the weight fraction of fruit juice in the first juice stream, asecond juice stream and a third juice stream are not the same.
 11. Amethod comprising: (a) providing a flow of vegetable juice that issubstantially free of insoluble vegetable solids; (b) dividing the flowof vegetable juice into at least a first juice stream, a second juicestream and a third juice stream by passing the flow of vegetable juicethrough a ratio divert mechanism; (c) treating the first juice stream topreferentially remove acidic compounds thereby creating anacids-enriched juice stream and an acids-reduced juice stream; (d)combining the acids-reduced juice stream with the second juice stream tocreate an acids-reduced vegetable juice; and (e) combining theacids-enriched juice stream with the third juice stream create anacids-enriched vegetable juice.
 12. The method of claim 11, furthercomprising concentrating the acids-enriched vegetable juice by removinga portion of the water therein.
 13. The method of claim 11, furthercomprising concentrating the acids-reduced vegetable juice by removing aportion of the water therein.
 14. The method of claim 11 wherein thevegetable juice is tomato or pepper juice.
 15. The method of claim 11wherein the step of treating a first portion of the vegetable juicecomprises nanofiltration.
 16. The method of claim 11 further comprisingcombining the acids-enriched vegetable juice with a different vegetablejuice to generate a blended juice product.
 17. The method of claim 11further comprising combining the acids-reduced vegetable juice with adifferent vegetable juice to generate a blended juice product.
 18. Themethod of claim 11 further comprising drying the acids-enrichedvegetable juice to generate an acids-enriched vegetable juice powder.19. The method of claim 11 further comprising drying the acids-reducedvegetable juice to generate an acids-reduced vegetable juice powder. 20.The method of claim 11 wherein the weight fraction of vegetable juice inthe first juice stream, a second juice stream and a third juice streamare not the same.